@mojophone, I was flying to China last year and was reading the inflight magazine and noticed the that you could use the United app for inflight services and entertainment, we were still at the gate and just started to be pushed back, the stewardess was making a finally walk through, I asked her about it and she said she thought I needed to go and register on the internet to gain access (but I wouldn't be able to do it from the plane), I was still close enough to the terminal and was able to quickly use its wifi to register
. this Service is not available on all planes/flights however.
My advice is to call the airlines, or go online to find out exactly what you need to do, BEFORE you get on the plane. It's hard to beat being able to watch streamed movies/TV shows, on a Surface Pro (plugged in under your seat), over a set of Bose Quiet Comfort 25 Black Acoustic Noise Cancelling Headphones, while cruising at 35K' on a 15/17hr flight